It's not perfect, but darn close! I just about have the steps dialed in, think I need to put a bit more into extrusion and the orthogonal is in the money...

@SIam said in Skewed Prints on CoreXY:

hi,

your X and Y stepps musst be the same if not you get your results

Okay, so this had the greatest impact. Setting X/Y steps to equal has things almost perfect. Diagnal measurement of print in nearly negligible, and probably have to adjust the belt tension ever slightly to get this final dimension dialled in.

Thanks so far! I will post some pics when I get a moment this weekend.

I did tweak my X-Axis a bit more and got a change that I am able to track the effects with a test cube and know I was adjusting in the wrong direction. Apparently measuring against the front frame seems logical, but the real issue may be with the Y brackets. I noticed it wasn't perpendicular to the setup, and that I am trying to correct that using tension on the belts. I don't currently have offset wheels to allow me to correct the Y mount geometry. Will get those if I must, but working towards installing side rails in the near future.

Good concept about the steps should be the same. The motors are the same 0.9° model from OMC, so it makes sense they shouldn't be all that much different if not identical. I know when printing my 100mm square that I get about ~100.3 mm in one direction and ~100.5mm in the other. So a little more tweaking needed there.

You have all given me some things to try. I will report back my findings. I am definitely learning something here.

@Phaedrux said in Skewed Prints on CoreXY:

@Gamefanatic3D said in Skewed Prints:

double checked my X axis alignment. The X axis was off about 3mm

What exactly do you mean by this?

Based on your picture I adjusted the distance between P1 and P3 to be equal to P2 and P4. So that the X-Axis extrusion was parallel to the front and rear extrusions.

Are your belts parallel where they need to be?

Not exactly sure what you mean by this, but they are straight. My belts are aligned such that there are no angles in their runs. Where as in this picture Belt J icomes in at an angle between β and P3, mine would be aligned straight.

@mrehorstdmd said in Skewed Prints on CoreXY:

Maybe more importantly, are the X and Y rails square?

When you tension the belts, the X axis angle relative to the Y axis will change. The end point of the tension adjustment is when the axes are square.

If I understand you correctly, I adjusted the tension on the belts to align my X-Axis parallel to the front frame, but only after I ensured that the frame was square.

Just uploading a picture of what is happening.

I found that my prints are not printing in a straight line. Squares/rectangles are ever so slightly coming out like a parallelogram. When measuring a few of my prints, I found what should have been a 90° angle along the X and Y coming out to 91.3°.

This is a CoreXY machine, and I have validated the frame is 90° square and double checked my X axis alignment. The X axis was off about 3mm originally, but even after the adjustment the prints aren't any better.

Any suggestions on how I might fix this?

I changed the Z limit to 0.05 and everything is working great! It's always the simplest things we overlook. Thank you for your help.

I upgraded to the v2.04 firmware with the new web control. Still getting used to it. I kind of liked the old interface where I could watch my job stats, control most interface items and still watch my web cam at the same time.

@Phaedrux
Thank you for the feedback. Not sure why I was able to get it down to 0.14, but that makes sense! I'll check it when I get home and report back.

Thanks for the heightmap tip, I'll make that move.

The only file that has changed recently is the config.g:
homeall_20190417.g
config-override_20190417.g
config_20191129.g

I had been holding off on upgrading until I got things all worked out, but I'll make an effort tonight or tomorrow.

I am using Firmware 2.02(RTOS) (2018-12-24b1), and I just recently started running into an issue with being unable to get the X-Axis to properly move to 0. I started down this journey when replacing my generic extruders with a BMG.

When I homed the printer and told it to go to Z0.2 it would actually be about 0.05 above the bed. So I figured I needed to rehome. Got it just touching the glass and performed a G92 Z0. Then did my typical G30 S-1 for the BLTouch, updated my config accordingly and restarted the printer.

Homing the printer again, running a Z0.2 and again I am back at being 0.05mm above the bed. So I figured I would manually adjust the BLTouch to the desired height settling on Z2.195.

Now when I move to Z0.2 I'm about as close to 0.2 above the bed as I can measure, but cannot get the bed (X-Axis) to move below Z0.14 unless I remove the Axis limits (M564 S0).

What am I missing here? Seems like I'm fighting some offset the printer is tracking that is 0.15mm in distance.